I could have asked more questions: James Murdoch

London, Mar 14: News Corp executive James Murdoch acknowledged on Wednesday that he could have done more to investigate the phone hacking scandal that has rocked Britain and threatened his place as the likely heir to his father's global media empire.

Murdoch's admission came in a detailed, seven-page letter written to British parliamentarians investigating the scandal. In it, he repeated his insistence that he knew nothing about the criminality which had taken place at the now-defunct News of the World tabloid newspaper, saying that the extent of the wrongdoing had been hidden from him by members of his staff.

"It would have been better if I had asked more questions," Murdoch said. "However the truth is that incomplete answers and what now appear to be false assurances were given to the questions that I asked."

Murdoch has already appeared twice before lawmakers, who grilled him in detail about what he knew about the phone hacking scandal and alleged attempts to bury evidence of any illegal activity. Murdoch was the one who signed off on a massive settlement to one of the first known victims of the practice, a deal which the company's former in-house lawyer has acknowledged was aimed at keeping a lid on the scandal.

But the cover-up failed after the Guardian and The New York Times revealed that phone hacking was endemic at paper, an expose which has led to dozens of arrests and resignations. Murdoch's father, Rupert, was forced to close the News of the World following an advertiser boycott.

Lawmakers are now sifting through the scandal's fallout in an effort to find out who was responsible. In a separate development, police said that a 51-year-old man has been arrested today on suspicion of intimidating a witness.